So a little while ago, I got a hornwort plant (which didn't last long thanks to my dad shutting off the light every day :< ) for my goldfish tank. Before putting it in the tank, I QT it in a bowl and put it next to my window for a week.

When it came time to put the plant in the tank, there were still a few chunks left behind that I just left in the bowl.

Well, for some reason I decided to look in there today and noticed I had snails! Two big ones, a few small ones, and I think a nest in the hornwort! I have no idea how they got there or what they are. Anyone have any idea?

Depending on the kind, some snails can actually be beneficial to the tank. They keep the algae off the sides, and are just cute to look at. However, if you do want to get rid of them, I would suggest getting a loach. Some people would advise against getting a fish to take care of a problem, but loaches worked for me.

He looks like a basic pond snail. Snails are actually beneficial for an aquarium as they break down solid waste so the bacteria can go to work on wastes faster. Not to mention they help with algae cleanup (which is a big problem in goldie tanks). Just plop him in with Ro. He'll be fine. If you want to keep the eggs, put them back in the bowl by the window. They will hatch, and when they are large enough you can put them in with Ro.

If they do start to overpopulate your aquarium, don't worry about getting anything to deal with them. Goldfish take care of that themselves. I have a hard time keeping snails alive in my tank for just that reason. Little piggies...